This invention relates generally to cellular telephones and more particularly to cellular capable multi-protocol telephones.
Mobile phones use cellular networks operating according to Global System for Mobile Communication (GSM) or Code-Division Multiple Access (CDMA) to send and receive calls. Although these cellular networks are widely accessible, calls made over these cellular networks are generally more expensive and cannot accommodate as many calling features as other types of networks.
In contrast, calls made over other networks such as Internet Protocol (IP) networks used to carry Voice over Internet Protocol (VoIP) are less expensive and support more extensive calling features than calls made over cellular networks. However, these IP networks are not always as accessible as cellular networks.
Accordingly, multi-protocol telephones have been developed that select which network is used to send or receive a phone call depending on network accessibility. These multi-protocol telephones are generally provisioned with two different telephone numbers to facilitate use with a cellular network and an IP network. When an IP network is accessible, a call is made over the IP network from the VoIP phone number; otherwise the cellular network carries the call made from the cellular phone number.
FIG. 1 shows an example operation of a prior art multi-protocol phone 30. The phone 30 has a cell phone number 96 and a VoIP phone number 97. When the cell phone portion of the phone 30 is used to call endpoint B, the call 98A travels over the cellular network 60. When the VoIP portion of the phone 30 is used to call endpoint B, the call 99 travels over the IP network 61.
Call-handling functions for the multi-protocol telephone 30 are facilitated by call-handling device 15 located at a VoIP service provider for phone 30. In order for the call-handling device 15 to provide these call-handling functions for an active incoming call, the incoming call to the multi-protocol phone 30 must be first received at the call-handling device 15. In other words, call-handling functions cannot be applied to incoming telephone calls directed to the cell phone number 96 for the multi-protocol telephone 30. Moreover, the call-handling device 15 provides Single Number Reach (SNR) functionality that is only available to incoming calls routed through the call-handling device 15.
Although all incoming IP calls are routed through call-handling device 15, incoming calls directly to the cell phone number 96 bypass the call-handling device 15. A problem can occur when the cellular portion of multi-protocol telephone 30 is used to make the call 98A over the cellular network 60 to the endpoint B. The cellular network 60 detects the telephone number 96 for the cellular portion of the multi-protocol telephone 30 and provides that originating telephone number 96 to the endpoint B via a Calling Line Identification (CLI) field. A person at the called endpoint may then use the cellular telephone number 96 provided by the CLI field to make a return call 98B. As a result, the return call 98B bypasses the call-handling device 15 and the multi-protocol phone 30 is denied call-handling features and SNR functionality for the duration of the returned call 98B.
One proposed partial solution requires all outbound mobile calls from the multi-protocol phone to automatically connect with the call-handling device at the VoIP service provider before being delivered to an endpoint. As a result, a call-handling device phone number for the multi-protocol phone is included in a CLI field for the call. The called party can then use the call-handling device phone number located in the CLI field to return the call to the call-handling device for the multi-protocol phone. Solutions involving connecting all outbound calls to the call-handling device are expensive to deploy and generally require new hardware in the cell phone and/or the call handling device. For these and other reasons, such solutions generally have not been accepted by the industry.
It is known that one can use Presentation CLI to allow an enterprise having several employees, each with their own direct telephone number, to make outbound calls that present a toll free “1-800” billing number for the enterprise in a CLI field of the outbound call. For example, a cellular network assigns the billing number to the CLI field of any calls from any of the employees' cellular telephones. This functionality allows the enterprise to mask the employees' telephone numbers so that returned calls are directed to a call center for the billing number. The use of Presentation CLI has generally been limited to the above-described example.
Accordingly, multi-protocol telephones having cellular capability currently do not fully support SNR and do not fully integrate with call-handling functionality. The disclosure that follows solves these and other problems.